You don't get it. These snakes already have a system fully functional for both environments, cold as well as warm. You just assume they should get an advantage by becoming better at producing hormones. But the hormone production is already there, fully functional, regulated and adaptive - when it's hot eggs are hatched when it's cold eggs are retained! In that article there is nothing to suggest your scenario of further adaptation is needed.

That is not an example of evolution. You have the burden of proof to show that the northerners are genetically changed regarding regulation of live birth due to the cold environment. 

But as for your question, yes I believe in natural selection.

The platypus is a curious case, I'll give you that. But it's also very unique and tricky to draw conclusions from.

Marsupials are not an evolutionary step between reptiles and mammals.

Garter snakes I already included since they belong to the "several examples of lizards" category. (a snake that is very similar to these snake-like lizards, skinks, in the article)

I don't get it? I get it fine, it's you who is (I think on purpose) failing to understand.

No system is ever fully formed, there is always the need for improvement when the environment requires it. Do you think humans just sprouted a fully formed opposable thumb one day? Or do you think it would have evolved from another "fully formed" organ when the thumb offered a new evolutionary advantage? 

In the case of the lizards the environment has changed, which has favoured those who can reproduce with this ability for at least this generation. If this trait is required from generation to generation then an advanced form of this will become the norm for that species. This "fully formed" mechanism will change. If this mechanism is required over an extended period of time an advanced form of this will eventually it will become the common place method of birth.

In the paper they effectively say that if this form of birth is retained over a period of many generations then it will lead to an evolution in reduced egg shell thickness which fits with the hypothetical model. This will be an evolution as a result of natural selection.

The eggs of most viviparous lizards are surrounded by some form of tertiary egg envelope during early stages of embryonic development, but the thickness of this structure is less than that of oviparous species (Blackburn, 1993a, 1998). Reduction in eggshell thickness is believed to be a necessary correlate to the evolution of viviparity because thick eggshells would impede respiratory gas exchange during prolonged uterine egg retention (Packard et al., 1977; but see Mathies and Andrews, 2000). If the evolution of viviparity is preceded by gradual increases in the length of intrauterine gestation, gradual reductions in eggshell thickness should also occur (Packard et al., 1977; Guillette, 1993; Qualls, 1996). This hypothesis is supported by interpopulational comparisons within three species of lizards that demonstrate an inverse correlation between length of uterine egg retention and eggshell thickness (Heulin, 1990; Heulin et al., 1992,2002; Mathies and Andrews, 1995; Qualls, 1996).

(source)

The scientists at work here clearly think that the lizards are genetically changing as a result of this. Thy more than suggest that further adaptation is necessary. You can take this as the proof if you like, but I know that regardless of how much proof I show you, you will never accept it.

You claim to accept natural selection, yet you have shown many times that you reject it, almost as an automated response. The weak don't reproduce, the fit do, the successful traits are passed on to the next generation, this is natural selection at work. Natural selection leads to an evolution.

Wow, my sentence structure and grammar sucks today. Good luck with reading my post lol.

Yeah I already understood that you see the potential for change in this (I do too, I'm not stupid), you want to talk evolution in general. I well understand that theory , how populations get isolated and how environmental pressure via natural selection works on them to refine genetical traits bla bla bla. A school boy understands that. But that is only theory. Theory =/= reality. We are discussing a specific case here, about these particular snakes.

I repeat (because I was the one who said this article doesn't show evolution at work and you was the one who opposed me): You have the burden of proof to show that the northerners are genetically changed regarding regulation of live birth due to the cold environment. Or else what we read in that article is not a case study of evolution in action.

It should be no secret that all living things adapt to their environment in some way. If the environment changes over a long period of time, so do the species living in it. Those that cannot adapt die off, those that adapt best carry on their genes to future generations because there are more of them. These future generations then take on new traits (beginning as genetic abnormalities) which, if favorable to the environment, will spread, and eventually the "abnormal" trait will become the dominant trait, because the creatures with these creatures with the favorable traits will outlast those without and pass on their genes.

This is the process of evolution, and natural selection. Dinosaurs for instance did not just magically begin as these giant dominant creatures, they began as tiny reptiles that gained an advantage over other forms of life by their speed and being able to walk on two legs, which eventually mushroomed into them becoming the dominant life form and becoming these gargantuan beasts. This seems like a relatively obvious scientific concept, yet some people still refuse to believe it, for religious reasons or whatever else.. The fact is, species are always evolving, either in response to a changing environment, or in gaining favorable traits that give them an advantage in the existing environment.

Of course, this is a process that extends over tens, even hundreds of thousands of years, so the idea that we could be witnessing a species beginning to take on a new trait in response to a new environment in our very short lifetime is very spectacular.

Slimebeast, you know that a study into the genes passed form generation to generation to support live birth in this specific lizard can't be done yet, that's the only reason you're asking for. It's dirty debating. Even if I did prove the genetic change in this particular species you would find something else that's a little more out of range.

We are discussing a particular case, but a particular case which fits into a well documented and understood model. For what it's worth you might as well ask me to go to Jupiter and drop a weight into it and measure the acceleration, so that we can prove that Jupiter obeys gravity like Earth does. We know the model works, we've defined it to the level that every case can use will fit into it. Yes we test the theory frequently, but we can say with a high degree of certainty what the acceleration of an object will be when dropping it towards another planet with a high degree of certainty because the model exists to work it out and it has stood up to rigorous testing. This is just like that.

Unfortunately the future isn't here and I can't yet prove to you that the genes in this specific lizard have changed to a statistically significant level, I'll be happy to do so if you can remind me in a few decades. But in the meantime I know genetic traits are passed on in every species, and I know that only the fit survive to do so. From this I can say with a high degree of certainty that continuing environmental pressures in these lizards will eventually lead to an evolution, like our case with gravity.

We've observed the evolution of vivparity in lizards many times.

"The evolution of viviparity has been well documented and observed many times. Squamate reptiles provide an excellent model system for studies on the evolution of viviparity because live-bearing reproduction has evolved in the Squamata at least 100 times (Blackburn, 1999), and complex placentae have evolved four or five times (Thompson and Speake, 2006). Many of the reptilian origins of viviparity have occurred at low taxonomic levels and in geologically recent times, potentially allowing a reconstruction of the transition to viviparity."

(source)

This case follows the same model as many cases that have been previously shown. I can't prove this case, but I can see that it has many of the hallmarks  of hundreds of extremely similar cases where evolution has occurred. To say that it's not evolution if I can't show you genetic evidence yet is just plain wrong.

This is not  exactly an example of "macroevolution" as these changes happen extremely fast according to the ToE. Some of what scientist though was "junk" DNA isn't junk at all. There are other cases where the enviroment seems to trigger some part of DNA to be active so the creature can adapt to it's enviroment in a very short time.   For Dinos to transform into birds it would require genetic code (information) already in programed in the Dinos DNA ready to become active.  Like you said Dinosaurs does not just magically tranform so it must have code (information) to make these tranformations. For example Snakes seems to have genetic code to have limbs so it would be no surprise if a snake evolve limbs or snakes had limbs in the past.

slimebeast is right, this isn't evolution.

This is an adaptation, possibly an adaptation that is simply a work-around that the skink has always been capable of. 

Now for the positive; this could become an evolution after a significant time period.

The basis of evolution is the change of gene structure based on environmental isolation. In the case of the skinks, they have:

a) environmental isolation, but not b) genetic difference (that we know of yet)

Over time environmental isolation leads to genetic differences because the majority of the species in isolation evolves according to genetics of the founding parents. Generally, the evolved ability is present in a small minority of the species, but once it becomes isolated, sometimes the trait becomes dominant if it improves reproductivity or survival.

Gradually, this trait becomes so genetically different the the species can no longer reproduce with the other side of the species.

Now, to counter slimebeast, taking off a sweater or putting one on is an ability that humans have to keep ourselves warm. However, most animals are capable of keeping themselves warm, it's just that we have figured out a way to make that ability mobile. Cats in the cold will hide under a house, but they can't take the house with them. So while the analogy is a good argument, you skim over the inherent evolution of wearing clothes in itself. Evolutions are almost never dramatic leaps of mutation, but co-adaptations that become a new ability, In the sense of clothing, those co-adaptations were "being able to hold things" and "being able to warm oneself". Those are two parts of an entirely new evolution. Humans aren't evolved to wear clothes. We are evolved to carry things and warm ourselves. 

Similarly in the skinks, they are evolved to  regulate their birthing method depending on temperature condition and they are evolved to carry eggs. These two traits may be combining to become "live birthing" skinks. I haven't read the actual article in the journal, so I don't know how pervasive these two traits already are in the skink population. What may end up happening is that only a small portion of skinks are capable of this egg regulation, but they will be become the dominant members of the isolated population. The only thing that's missing here is why they would live in the colder temperatures. There needs to be a motivation.

For example, if caves were full of food and warmth, humans would never need to wear clothing. Humans wore clothing because the north had clean water, lots of large wild animals, and less poisonous insects and vermin. It was natural to move there.

Now, if they can show me why the skinks are preferring to live in colder areas, I would have the proof I need to call this potential evolution, which it is.

If I may, I think what's happening here is that Slimebeast simply hasn't saw enough evidence that, on this case, there's any difference at all between these lizards. They might just be reacting, through the same mechanism, to their different habitats.

Now, I think a simple experiment of taking a group from the south to the north and another from the north to the south could settle that well enough. That or sequencing their genomes :P